英文:
struct literal uses unkeyed fields
问题
我的目标是将函数嵌入到现有类型中。
我正在遵循《Effective Go》（https://go.dev/doc/effective_go#arrays）。
问题是它警告说var parent *embedding.Parent github.com/kidfrom/learn-golang/embedding.Child struct literal uses unkeyed fields。
目前的解决方案是创建NewChild(parent *Parent) *Child。然而，我担心这只是在愚弄编译器，将来可能会出现意外的错误，那么我做错了什么？
func NewChild(parent *Parent) *Child {
return &Child{parent}
}
cmd/test/main.go
package main
import "github.com/kidfrom/learn-golang/embedding"
func main() {
parent := &embedding.Parent{}
child := &embedding.Child{parent} // 它警告说`var parent *embedding.Parent github.com/kidfrom/learn-golang/embedding.Child struct literal uses unkeyed fields`
child.CallParentMethod()
}
embedding.go
package embedding
import "fmt"
type Parent struct{}
func (p *Parent) parentMethod() {
fmt.Println("parent method")
}
type Child struct {
*Parent
}
func (c *Child) CallParentMethod() {
c.parentMethod()
}
英文:
My goal is to embed function to an existing type.
I am following Effective Go
The problem is it warns var parent *embedding.Parent.
github.com/kidfrom/learn-golang/embedding.Child struct literal uses unkeyed fields
The current solution is to create NewChild(parent *Parent) *Child. However, I am afraid that this is just tricking the compiler and in the future it will panic unexpectedly, so what am I doing wrong?
func NewChild(parent *Parent) *Child {
return &Child{parent}
}
cmd/test/main.go
package main
import "github.com/kidfrom/learn-golang/embedding"
func main() {
parent := &embedding.Parent{}
child := &embedding.Child{parent} // it warns `var parent *embedding.Parent
github.com/kidfrom/learn-golang/embedding.Child struct literal uses unkeyed fields`
child.CallParentMethod()
}
embedding.go
package embedding
import "fmt"
type Parent struct{}
func (p *Parent) parentMethod() {
fmt.Println("parent method")
}
type Child struct {
*Parent
}
func (c *Child) CallParentMethod() {
c.parentMethod()
}
答案1
得分: 5
你收到的警告很可能来自go-staticcheck。运行以下命令也会看到类似的警告：
$ go vet
./main.go:8:12: github.com/kidfrom/learn-golang/embedding.Child composite literal uses unkeyed fields
检查你导入的包的文档：
$ go doc "github.com/kidfrom/learn-golang/embedding" Child
package embedding // import "github.com/kidfrom/learn-golang/embedding"
type Child struct {
*Parent
}
func NewChild(parent *Parent) *Child
func (c *Child) CallParentMethod()
显示在Child中嵌入的类型是Parent，所以为了修复警告，需要显式地给这个（嵌入的结构体）字段赋值：
child := &embedding.Child{Parent: parent}
英文:
The warning you are getting is most likely from go-staticcheck. You'd also see a similar warning by running:
$ go vet
./main.go:8:12: github.com/kidfrom/learn-golang/embedding.Child composite literal uses unkeyed fields
Checking the docs of the package you are importing:
$ go doc "github.com/kidfrom/learn-golang/embedding" Child
package embedding // import "github.com/kidfrom/learn-golang/embedding"
type Child struct {
*Parent
}
func NewChild(parent *Parent) *Child
func (c *Child) CallParentMethod()
shows the embedded type within Child is Parent, so to fix the warning explicitly assign the value to this (embedded struct) field:
child := &embedding.Child{Parent: parent}
答案2
得分: 1
你可以通过在Child结构体中的*Parent属性上添加一个键来解决警告。示例代码如下：
type Child struct {
Parent *Parent
}
然后在main函数中调整child属性的初始化，如下所示：
child := &embedding.Child{Parent: parent}
英文:
You can fix the warning by adding a key to your *Parent attribute within the Child struct. Example:
type Child struct {
Parent *Parent
}
and adjust the initialization of your child attribute in your main func as followed:
child := &embedding.Child{Parent: parent}
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